Light scattering means that many synthetic oil-repellent surfaces are opaque, limiting their use. A transparent, oil-repellent surface would have applications in biology and underwater optics, including in diving goggles and cameras. Now, Feng Chen’s research group at Xi’an Jiaotong University has developed such a material.
Fish repel oil by trapping water within their scales to create a self-cleaning, oil-repellent coat and prompted part of the idea behind the work. Chen’s other brainwave was triggered by Diphylleia grayi – also known as the skeleton flower.
In air Diphylleia grayi’s petals appear white, but on contact with water they become transparent. This change is not due to a pigment but loose cell structure in the plant petals. On sunny days the air–liquid interface of the petals causes diffuse reflectance, endowing the petals with a white colour, whilst on rainy days water enters the petals, yielding a water–water interface, increasing light transmission so they turn transparent.
By using femtosecond laser ablation to create rough nanostructures on a silica glass surface, Chen and his team have made a surface that combines both of these systems – it turns transparent and repels oil when in water. Chen’s student, Jiale Yong, highlights the value of ‘realising the importance of having a trapped water layer’ as they hope to ‘apply the transparent oil-repellent material in underwater oil-repellent optical devices’.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.